Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
345 PM EDT Thu Aug 30 2018

Valid Aug 30/1200 UTC thru Sep 03/0000 UTC

...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...

12Z model evaluation with final preferences and confidence
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...Overall Synoptic Pattern across the CONUS...
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Preference: Blend of the 12Z GFS/12Z ECMWF...more weight on GFS
Confidence: Average

The large scale upper pattern will feature a series of progressive
shortwaves advancing across southern Canada and the northern tier
of the U.S. through the short range period, with the general
tendency for a mean layer trough to focus over the Intermountain
West and a rather strong mid level subtropical ridge to remain in
place over the eastern U.S.

The 12Z NAM stood out the greatest from the remaining model
guidance regarding timing/amplitude of features and is considered
the least likely to verify through Sunday. Other timing
differences noted with the 00Z UKMET across the Great Lakes region
concerning a cold front were resolved in the 12Z UKMET adjusting
closer to the remaining model consensus. Across the Southwest,
some minor timing differences remained with the longitude of a
trough axis by Saturday/Sunday, but the 12Z ECMWF/UKMET/CMC showed
some adjustment toward the NAM/GFS with differences relatively
minor. Elsewhere across the U.S., differences between the latest
12Z guidance were small enough to support a general model blend.

Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml

Otto